1. Field of the Invention
The present invention relates to numerical control devices and, more particularly, to a numerical control device for a machine tool that performs a variety of cutting operations.
2. Description of the Related Art
A servo control system for a feed drive system (control axis) of a numerically controlled machine tool has optimum values for a servo gain, a velocity controlled value and a corrected value (corrected value for backlash) during reversed rotation of the axis, respectively, with parameters of the optimum values having influences a machining accuracy, such as a surface roughness and shape accuracy or the like, and a machining time interval.
In a related art, the servo control system has no function for enabling optimum servo tunings to be executed for respective machining operations, with an inability of executing the optimum servo tunings for the respective machining operations. Thus, for every machining operations, it is a general practice to set a typical parameter by which an affect is offered to some extent. Further, with a special purpose machine tool specifically structured for performing a specific machining operation, it is a usual practice for a specific tuning to be implemented so as to meet such a particular machining operation each time the special purpose machine tool is manufactured and delivered.